Robotically controlled medical instrument

ABSTRACT

A medical instrument assembly comprises a shaft, a tool carried by the distal end of the shaft for performing a medical procedure on a patient, an end effector, a threaded housing in which the threaded distal shaft end is configured for being screwed, and a first threaded piece disposed in the threaded housing and configured for being moved to actuate the end effector. The assembly further comprises an actuation element extending within the shaft. The actuation element includes a second threaded piece that distally extends from the threaded distal shaft end. The second threaded piece is configured for being screwed to the first threaded piece. A robotic system comprises the assembly, a user interface configured for generating command(s), a drive unit coupled to the actuating element, and an electric controller configured, in response to the command(s), for directing the drive unit to move the actuating element to actuate the tool.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.10/976,066, filed Oct. 28, 2004, which is a continuation of U.S.application Ser. No. 10/299,588, filed Nov. 18, 2002 (now abandoned),which claims the benefit of U.S. Provisional Application Nos.60/332,287, filed Nov. 21, 2001, 60/344,124, filed Dec. 21, 2001, and60/382,532, filed May 22, 2002, and is a continuation-in-part of U.S.application Ser. No. 10/014,143 (now abandoned), Ser. No. 10/008,964(now abandoned), Ser. No. 10/013,046 (now abandoned), Ser. No.10/011,450 (now abandoned), Ser. No. 10/008,457 (now U.S. Pat. No.6,949,106), Ser. No. 10/008,871 (now U.S. Pat. No. 6,843,793), all filedNov. 16, 2001, and Ser. No. 10/012,845, filed Nov. 16, 2001 (now U.S.Pat. No. 7,169,141), each of which claim the benefit of U.S. ProvisionalApplication No. 60/279,087, filed Mar. 27, 2001.

U.S. application Ser. No. 10/299,588 is also a continuation-in-part ofU.S. application Ser. Nos. 10/023,024 (now abandoned), 10/011,371 (nowU.S. Pat. No. 7,090,683), 10/011,449 (now abandoned), 10/010,150 (nowU.S. Pat. No. 7,214,230), 10/022,038 (now abandoned), 10/012,586, allfiled on Nov. 16, 2001, and all of which claim the benefit of U.S.Provisional Application Nos. 60/269,200, filed Feb. 15, 2001,60/276,217, filed Mar. 15, 2001, 60/276,086, filed Mar. 15, 2001,60/276,152, filed Mar. 15, 2001, and 60/293,346, filed May 24, 2001.

This application is also related to application Ser. Nos. 12/024,039 and12/023,981, both of which are filed on the same date herewith.

The entire teachings of the above applications are incorporated hereinby reference.

BACKGROUND OF THE INVENTION

Various types of instruments are used to perform surgical procedures onliving subjects such as human patients. Typically, in the past, thesurgeon held the instrument and inserted it into the patient to aninternal surgical site. The surgeon then manually manipulated theinstrument to perform the operation at the site. These instruments havebeen used to perform a number of surgical procedures including holding aneedle to suture a region of the surgical site, cutting tissue, andgrasping tissue and blood vessels.

Recently, some have proposed using telerobotic surgical systems toperform certain surgical procedures. With these systems, the surgeonsits at a master station remotely located from the patient and surgicalinstrument, and controls the movements of the surgical instrument withan input device. In some systems, the surgeon manipulates the inputdevice with one or both hands, and the instrument replicates the handand finger movements of the surgeon. Because these replicated movementscan be quite complex, the surgical instrument is controlled to move withmultiple degrees-of-freedom.

SUMMARY OF THE INVENTION

In accordance with a first aspect of the present inventions, a medicalinstrument assembly is provided. The medical instrument assemblycomprises an elongated shaft having, and a tool carried by the distalend of the elongated shaft for performing a medical procedure on apatient. The tool includes an end effector, a threaded housing in whichthe threaded distal end of the shaft is configured for being screwed,and a first threaded piece disposed in the threaded housing andconfigured for being moved to actuate the end effector. In oneembodiment, the first threaded piece has more threads per inch than thethreads of the threaded housing. In another embodiment, the firstthreaded piece is centered within the threaded housing. In still anotherembodiment, the end effector includes a pair of jaw members that openand close when actuated, and the tool further includes linkage coupledbetween the jaw members and the first threaded piece, such that axialmovement of the actuating element opens and closes the jaw members.

The medical instrument assembly further comprises an actuation elementextending within the elongated shaft. The actuation element includes asecond threaded piece that distally extends from the threaded distal endof the elongated shaft. The second threaded piece is configured forbeing screwed to the first threaded piece of the tool. In oneembodiment, the first threaded piece has female threads, and the secondthreaded piece has male threads. In another embodiment, the secondthreaded piece is configured for being linearly displaced relative tothe threaded distal end of the elongated shaft. In this case, theactuating element may include a block proximal to the second threadedpiece, and the threaded distal end of the elongated shaft may include apair of arms configured for engaging the block to prevent the secondthreaded piece from rotating relative to the threaded distal end of theelongated shaft. In still another embodiment, the elongated shaft of theactuation element is a cable. In this case, the actuation element mayfurther include a sleeve disposed about the cable to prevent compressionof the cable, and a helical spring disposed about the respective sleeve.

In an optional embodiment, the medical instrument assembly furthercomprises a controllably bendable section associated with elongatedshaft and disposed proximal to the tool, another actuation elementconfigured for actuating the controllably bendable section, and meansfor decoupling motion at the controllably bendable section from the toolactuation. In another optional embodiment, the medical instrumentassembly further comprises an instrument coupler mounted to the proximalend of the elongated shaft, with the instrument coupler carrying arotatable wheel to which the actuation element is mounted. The medicalinstrument assembly may further comprise an adapter coupler to which theinstrument coupler is configured for being removably mated, with theadapter coupler having a complementary wheel that mechanicallyinterfaces with the wheel of the instrument coupler. The medicalinstrument assembly may further comprise cabling extending from theadapter coupler and configured for coupling a drive unit to thecomplementary wheel. The medical instrument assembly may furthercomprise a carriage on which the instrument coupler is mounted.

In accordance with a second aspect of the present inventions, a roboticmedical system is provided. The robotic medical system comprises thepreviously described medical instrument assembly, a user interfaceconfigured for generating at least one command, a drive unit (e.g., onehaving a motor array) coupled to the actuating element of the medicalinstrument assembly, and an electric controller configured, in responseto the command(s), for directing the drive unit to move the actuatingelement to actuate the tool.

In one embodiment, the command(s) comprises movements at the userinterface, and the electric controller is configured for directing thedrive unit to move the actuating element to effect movements of the toolcorresponding to the movements at the user interface. In anotherembodiment, the user interface is located remotely from the drive unit,the electrical controller is coupled to the drive unit via externalcabling, and the drive unit is coupled to the actuating element viaexternal cabling.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages of theinvention will be apparent from the following more particulardescription of preferred embodiments of the invention, as illustrated inthe accompanying drawings in which like reference characters refer tothe same parts throughout the different views. The drawings are notnecessarily to scale, emphasis instead being placed upon illustratingthe principles of the invention.

FIG. 1 is a perspective view illustrating a telerobotic system withwhich the concepts of the present invention may be practiced;

FIG. 2 is a schematic diagram illustrating the degrees-of-freedomassociated with the slave station of FIG. 1;

FIG. 3 is a plan view of the instrument insert of the present inventionincluding the stem section and tool;

FIG. 4 is a cross-sectional view as taken along line 4-4 of FIG. 3 andillustrating further details of the stem section;

FIG. 5 is a perspective view of another embodiment of the tool of thepresent invention employing a flexible wrist section adjacent the tool;

FIG. 6 is an exploded perspective view of the embodiment of FIG. 5;

FIG. 7 is a cross-sectional view of the embodiment of FIG. 5 and astaken along line 7-7 of FIG. 6;

FIG. 8 is a longitudinal cross-sectional view of the embodimentillustrated in FIGS. 5-7 and showing further details at the wristflexure;

FIG. 9 is a longitudinal cross-sectional view similar to that shown inFIG. 8 but for still another embodiment of the present invention using asingle actuation element;

FIG. 10 is an enlarged fragmentary view of further details of theactuation element at the center of the wrist section;

FIG. 11 is a cross-sectional view through the actuation element of FIG.10 as taken along line 11-11;

FIG. 12 is a cross-sectional view through still another embodiment ofthe actuation element;

FIG. 13 is still a further cross-sectional view of a further embodimentof the actuation element;

FIG. 14 is a perspective view of yet another embodiment of the presentinvention employing a slotted flexible wrist section and a detachableand preferably disposable tool;

FIG. 15 is a cross-sectional view through the embodiment of FIG. 14 astaken along line 15-15 of FIG. 14;

FIG. 15A is a fragmentary cross-sectional view of an alternateembodiment of the flexible section;

FIG. 16 is an exploded perspective view of the embodiment of FIG. 14showing the detached tool in cross-section;

FIG. 17 is a further perspective view of the embodiment of FIG. 14;

FIGS. 18-20 illustrate sequential cross-sectional views showing themating of the tool with the distal end of the instrument;

FIG. 21 is a schematic diagram illustrating principles of the presentinvention in a catheter or flexible instrument using multiplecontrollable bendable sections along the instrument;

FIG. 22 is a schematic diagram of an embodiment of an instrument withboth elbow and wrist pivot joints, as well as a disposable tool;

FIG. 23 is a schematic diagram of an embodiment of an instrument withjust a wrist pivot joint, as well as a disposable tool;

FIG. 24 is a diagram showing further details of a wrist joint useablewith a disposable tool;

FIG. 25 is a partially cut-away schematic view of another jointconstruction;

FIG. 26 is a perspective view of a another embodiment of a tool;

FIG. 27 is an exploded perspective view of the tool of FIG. 26illustrating separate components thereof;

FIG. 27A is an exploded fragmentary view of one form of resilient memberused in the embodiment of FIG. 27;

FIG. 27B is an exploded fragmentary view of another form of resilientmember used in the embodiment of FIG. 27;

FIG. 28 is a side elevation view of the tool depicted in FIGS. 26 and27;

FIG. 29 is an enlarged partial top plan view as seen along line 29-29 ofFIG. 28 and illustrating further details of the tool;

FIG. 30 is a cross-sectional view as taken along line 30-30 of FIG. 29showing the tool of the present invention with the jaws in a partiallyopen position;

FIG. 31 is a cross-sectional view like that illustrated in FIG. 30 butwith the jaws in a fully closed position;

FIG. 32 is a somewhat schematic cross-sectional view of the firstembodiment of the tool with the resilient pad partially compressed ingrasping a small diameter item such as a thread or suture;

FIG. 33 is a somewhat schematic cross-sectional view of the firstembodiment of the tool with the resilient pad essentially fullycompressed in grasping a larger diameter item such as a needle;

FIG. 34 is a perspective view of a second embodiment of the inventionemploying a flexure gap in one of the jaws;

FIG. 35 is an exploded perspective view of the tool of this secondembodiment of the invention;

FIG. 36 is a plan view of the tool of FIGS. 34 and 35;

FIG. 37 is a cross-sectional view taken along line 37-37 of FIG. 36 withthe jaws having a slight gap at their closed position;

FIG. 38 is a cross-sectional view like that illustrated in FIG. 37 butwith the jaws grasping a needle or the like, and with the flexure gap ina substantially closed position;

FIG. 39 is a cross-sectional view similar to that depicted in FIGS. 37and 38, and of yet another embodiment of the invention illustrating thetool in a partially open position;

FIG. 40 is a cross-sectional view the same as that depicted in theembodiment of FIG. 39 but with the jaws in a more closed position;

FIG. 41 is a perspective view of an embodiment of a flexible or bendableshaft segment just proximal to the tool;

FIG. 42 is a cross-sectional view of the embodiment of FIG. 41 as takenalong line 17-17 of FIG. 16, and with the jaws in a substantially openposition;

FIG. 43 is an enlarged partial cross-sectional view similar to thatshown in FIG. 42 but with the jaws in a closed position;

FIG. 44 is an exploded perspective view showing the components includingthe flexible or bendable segment of FIG. 41;

FIG. 45 is a side elevation view of the flexible or bendable sectionitself;

FIG. 46 is a cross-sectional view through the flexible or bendablesection as taken along line 46-46 of FIG. 45;

FIG. 47 is a cross-sectional view through the flexible or bendablesection as taken along line 47-47 of FIG. 45;

FIG. 48A is a perspective view of an alternate embodiment of the tooland flexible section;

FIG. 48B is an exploded perspective view of the tool and flexiblesection illustrated in FIG. 48A;

FIG. 48C is a fragmentary perspective view showing a portion of theflexible section shown in FIG. 48B; and

FIG. 48D is a plan view of the flexible section illustrated in FIGS.48A-48C.

FIG. 49 illustrates a flexible instrument being used in a stomach of asubject in accordance with the invention.

FIG. 50A is a schematic of a flexible instrument with a pull-type cableto operate the end of the instrument in accordance with the invention.

FIG. 50B is cross-sectional view of a bendable section of the flexibleinstrument of FIG. 50A in accordance with the invention.

DETAILED DESCRIPTION OF THE INVENTION

A description of preferred embodiments of the invention follows.

The surgical robotic system of the present invention, as illustrated inthe accompanying drawings, although preferably used to perform minimallyinvasive surgery, can also be used to perform other procedures as well,such as open or endoscopic surgical procedures. FIG. 1 illustrates asurgical instrument system 10 that includes a master station M at whicha surgeon 2 manipulates an input device, and a slave station S includinga surgical instrument illustrated generally at 14. In FIG. 1 the inputdevice is illustrated at 3 being manipulated by the hand or hands of thesurgeon. The surgeon is illustrated as seated in a comfortable chair 4,and the forearms of the surgeon are typically resting upon armrests 5.

FIG. 1 illustrates a master assembler 7 associated with the masterstation a and a slave assembly 8, also referred to as a drive unit,associated with the slave station S. Assemblies 7 and 8 areinterconnected by cabling 6 with a controller 9, which typically hasassociated with it one or more displays and a keyboard.

As shown in FIG. 1, the drive unit 8 is located remotely from theoperative site and is preferably positioned a distance away from thesterile field. The drive unit 8 is controlled by a computer system thatis part of the controller 9. The master station M may also be referredto as a user interface vis-vis the controller 9. The computer translatesthe commands issued at the user interface into an electronically drivenmotion in the drive unit 8, and the surgical instrument, which istethered to the drive unit through the cabling connections, produces thedesired replicated motion. That is, the controller 9 couples the masterstation M and the slave station S and is operated in accordance with acomputer algorithm, to be described in further detail below. Thecontroller 9 receives a command from the input device 3 and controls themovement of the surgical instrument 14 so as to replicate the inputmanipulation. FIG. 1 also shows a patient P, upon whom the surgicalprocedure is performed, lying on an operating table T.

In the embodiment illustrated in FIG. 1, the surgical instrument 14includes two separate instruments one on either side of an endoscope 13.The endoscope 13 includes a camera to remotely view the operation site.The camera may be mounted on the distal end of the instrument insert, ormay be positioned away from the site to provide an additionalperspective on the surgical operation. In certain situations, it may bedesirable to provide the endoscope through an opening other than the oneused by the surgical instrument 14. In this regard, in FIG. 1 threeseparate incisions are shown in the patient P, two side incisions foraccommodating the surgical instruments and a central incision thataccommodates the viewing endoscope. A drape covering the patient is alsoshown with a single opening.

The surgical instrument 14 also includes a surgical adaptor or guide 15and an instrument insert or member 16. The surgical adaptor 15 isbasically a passive mechanical device, driven by the attached cablearray. Although the surgical adaptor can be easily seen in FIG. 1, theinstrument member 16 (FIG. 3) is not clearly illustrated as it extendsthrough the adaptor 15. The instrument insert 16 carries at its distalend a tool 18, described in greater detail below.

Although reference is made herein to a “surgical instrument,” it iscontemplated that the principles of this invention also apply to othermedical instruments, not necessarily for surgery, and including, but notlimited to, such other implements as catheters, as well as diagnosticand therapeutic instruments and implements.

In FIG. 1 there is illustrated cabling 12 coupling the instrument 14 tothe drive unit 8. The cabling 12 is preferably detachable from the driveunit 8. Furthermore, the surgical adaptor 15 may be of relatively simpleconstruction. It may thus be designed for particular surgicalapplications such as abdominal, cardiac, spinal, arthroscopic, sinus,neural, etc. As indicated previously, the instrument insert 16 couplesto the adaptor 15, and essentially provides a means for exchanging theinstrument tools. The tools may include, for example, forceps, scissors,needle drivers, electrocautery, etc.

During use, a surgeon can manipulate the input device 3 at a surgeon'sinterface 11, to effect a desired motion of the tool 18 within thepatient. The movement of the handle or hand assembly at input device 3is interpreted by the controller 9 to control the movement of the tool18.

The surgical instrument 14 is preferably mounted on a rigid post 19 thatis affixed to but removable from the surgical table T. This mountingarrangement permits the instrument to remain fixed relative to thepatient even if the table is repositioned. In accordance with thepresent invention the concepts can be practiced even with a singlesurgical instrument, although, in FIG. 1 there are illustrated two suchinstruments.

The surgical instruments 14 are connected to the respective drive units8 with cablings that include two mechanical cable-in-conduit bundles 21and 22. These cable bundles 21 and 22 may terminate at two connectionmodules, which removably attach to the drive unit 8. For further detailsof the connection modules 23 and 24 can be found in the earlierco-pending application No. PCT/US00/12553, the entire contents of whichare incorporated herein by reference. Although two cable bundles aredescribed here, it is to be understood that more or fewer cable bundlescan be used. Furthermore, although the drive unit 8 is preferablylocated outside the sterile field, it may be draped with a sterilebarrier so that it can be operated within the sterile field.

In the preferred technique to set up the system, the tool 18 of thesurgical instrument 14 is inserted into the patient through an incisionor opening, and the instrument 14 is then mounted to the rigid post 19using a mounting bracket 25. The cable bundles 21 and 22 are thenextended away from the operative area to the drive unit 8, and theconnection modules of the cable bundles are engaged into the drive unit8. Instrument inserts 16 (FIG. 3) may then be passed through thesurgical adaptor 15, and coupled laterally with the surgical adaptor 15through an adaptor coupler, as described below in further detail.

As just mentioned, the instrument 14 is controlled by the input device3, which is manipulated by the surgeon. Movement of the hand assemblyproduces proportional movement of the instrument 14 through thecoordinating action of the controller 9. It is typical for the movementof a single hand control to control movement of a single instrument.However, FIG. 1 shows a second input device that is used to control anadditional instrument. Accordingly, in FIG. 1 two input devicesassociated with the two instruments are illustrated.

The surgeon's interface 11 is in electrical communication with thecontroller 9 primarily by way of the cabling 6 through the masterassembly 7. Cabling 6 also couples the controller 9 to the actuation ordrive unit 8. While the cabling 6 transmits electrical signals, theactuation or drive unit 8 is in mechanical communication with theinstrument 14. The mechanical communication with the instrument allowsthe electromechanical components to be removed from the operativeregion, and preferably from the sterile field. The surgical instrument14 provides a number of independent motions, or degrees-of-freedom, tothe tool 18. These degrees-of-freedom are provided by both the surgicaladaptor 15 and the instrument insert 16.

Shown in FIG. 2 is a schematic representation of the joint movementassociated with the slave station S. The first joint movement J1represents a pivoting notion of the instrument about the pivot pin 225at axis 225A. Also illustrated is the movement relating to joint J2which is a transitional movement of the carriage 226 on the rails 224 tomove the carriage as well as the instrument 14, supported therefrom, inthe direction indicated by the arrow 227 in FIG. 2 towards and away fromthe operative site OS. The cabling in the bundle 21 controls both the J1and J21 movements. It is further noted that the distal end of the guidetube 17 extends to the operation site OS. The operation site may bedefined as the general area in close proximity to where movement of thetool occurs, usually in the viewing area of the endoscope and away fromthe incision.

FIG. 2 also depicts the rotary motion of both the adaptor tube 17 andthe instrument stem. These are illustrated in FIG. 2 as respectivemotions or joints J3 (adaptor tube rotation) and J4 (instrument stemrotation). Motion J5 indicates a wrist pivot or, alternatively, a wristflexure. Finally, motions J6 and J7 represent the end jaw motions of thetool 18.

The combination of joints J4-J7 allows the instrument insert 16 to beactuated with four degrees-of-freedom. When coupled to the surgicaladaptor 15, the insert 16 and adaptor 15 provide the surgical instrument14 with seven degrees-of-freedom. Although four degrees-of-freedom aredescribed here for the instrument insert 16, it is to be understood thatgreater or fewer numbers of degrees-of-freedom are possible withdifferent instrument inserts. For example an energized insert with onlyone gripper may be useful for electro-surgery applications, while aninsert with an additional linear motion may provide stapling capability.

With regard to the incision point, FIG. 2 shows the incision point alongthe dashed line 485, and a cannula 487 that in some surgical proceduresis used in combination with a trocar to pierce the skin at the incision.The guide tube 17 is inserted through the flexible cannula 487 so thatthe tool is at the operative site OS. The cannula typically has a portat which a gas such as carbon dioxide enters for insufflating thepatient. The cannula also is usually provided with a switch or buttonthat can be actuated to desufflate. The cannula is used primarily forguiding the instrument, but may include a valve mechanism for preventingescape of gas from the body.

FIG. 3 is a plan view showing an instrument insert including the tool18, and elongated sections including a rigid section 302 and a flexiblesection 303, with the tool 18 mounted at the end of the flexible stemsection 303. The coupler 300 includes one or more wheels that laterallyengage wheels of the coupler associated with the surgical adaptor. Thecoupler 300 also includes an axial wheel 306 that also engages a wheelon the adaptor. The axial engagement wheel 306 is fixed to the rigidstem 302, and is used to rotate the tool axially at the distal end ofthe flexible stem section 303.

FIG. 3 illustrates the base coupler 300 of the instrument insert 16 withwheels 330, 332, and 334 that have half-moon construction for engagementwith mating like wheels of the adaptor. These wheels are meant to matewith the corresponding wheels of the adaptor. Also illustrated in FIG. 3are capstans or idler pulleys 340, 342, and 344 associated with wheels330, 332, and 334, respectively.

Each wheel of the coupler has two cables that are affixed to the wheeland wrapped about opposite sides at its base. The lower cable rides overone of the idler pulleys or capstans, which routes the cables toward thecenter of the instrument stem 302. The cables are kept near the centerof the instrument stem, since the closer the cables are to the centralaxis of the stem, the less disturbance the cables experience as the stemsection moves (rotates). The cables may then be routed individuallythrough plastic tubes that may be affixed, respectively, to the proximalend of the rigid stem 302 and the distal end of the flexible stemsection 303. Alternatively, the cables may each be enclosed in separateplastic tubes or sheathes only in the flexible section of the instrumentstem (see, e.g., bundle 284 in FIG. 4). The tubes assist in maintainingconstant length pathways for the cables as they move longitudinallywithin the instrument stem.

As for the coupler 300, there are six cables that connect to each of thewheels. Two cables connect to each wheel and one of these cables extendsabout the associated idler pulley or capstan. These are illustrated inFIG. 3 as idler pulleys 340, 342 and 344. Thus, six separate cablesextend through the rigid stem 302 and down through the flexible stemsection 303 to the area of the tool.

Associated with the wheels 330, 332, and 334 are six cables that extendthrough the sections 302 and 303, as illustrated in FIG. 4. One set ofthese cables controls the pivoting, such as the pivoting movement aboutpin 620. The other cables control the operation at the gripping jaws.For example, one pair of cables may control the movement of the lowerjaw 652, while another cable pair may control the operation of the upperjaw 650.

In FIG. 4 there is shown the rigid section 302 and the flexible section303 of the instrument insert 16. A series of six cables, illustrated atarrow 280 in FIG. 4 extend through these sections and may be consideredas separated into three sets for controlling the tool 18, to provide themotions indicated in FIG. 2 as J5-J7. To de-couple wrist control fromjaw control, the cabling is supported near to the center axis of therigid and flexible sections. Note that “de-coupling” simply means thatany one controlled action associated with the tool, when performed, doesnot interfere with other controlled actions that may not be selected atthe time that the one controlled action is taking place. This may becontrolled to some extent by using a retainer block 282 within thesesections between the sections 302 and 303, as depicted in FIG. 4. On therigid section side of the block 282 the cables may be unsupported asshown or they could be held within a plastic sleeve either individuallyand/or as a group. Because the cables are maintained in tension and therigid section is not meant to bend or flex, the cables can be held inposition by being supported, as a group, at the center of block 282.

From the other side of block 282 the cables extend through in a bundle284. Also, each individual cable is preferably held within a cablesleeve, such as illustrated in FIGS. 6 and 8, to be described later infurther detail. Also, as shown in FIG. 8 the cables contained in thesleeves 292 are twisted, for example, 180 degrees over say 8 inches. Asalso shown in FIG. 4, spacers 286 may be spaced along the flexiblesection 303 to hold the bundle 284 at the center of the section 303. Theindividual cable sleeves also define a substantially fixed lengthpathway for each cable so that even though the instrument may move orrotate, the cable lengths should stay the same within the flexible stemsection. The sleeves may be held in fixed position at their ends such asat block 282 at one end and at the tool 18 at the other end. The outerflexible tube 288 may be a pliable plastic preferably having a fluted orbellows-like configuration, as illustrated.

The limited twisting of the cable bundle prevents the formation of kinksor loops in individual cables that might occur if the cables werestraight and parallel through the flexible section. This twisting alsoprovides the de-coupling between motions, so that actuation of one ofthe degrees-of-freedom (J5-J7) does not cause a responding action atanother degree-of-freedom (J5-J7). The twisting essentially occursbetween the block 282 and the location where the bundle enters the wristjoint (for example, the entry to base 600). The 180 degree twisting ofthe bundle ensures that the cable sheathes are neither stretched norcompressed, even as the bendable section is bent or rotated.

The construction of one form of tool is illustrated in FIGS. 3 and 4.The tool 18 includes the base 600, link 601, upper grip or jaw 650 andlower grip or jaw 652. The base 600 is affixed to the flexible stemsection 303. As illustrated in the drawings, this flexible section maybe constructed of a ribbed plastic. This flexible section allows theinstrument to readily bend through the curved actuator tube 17.

The link 601 is rotatably connected to the base 600 about an axis 620Arepresented by pivot pin 620. The upper and lower jaws 650 and 652 arerotatably connected to the link about axis 605, where axis 605 isessentially perpendicular to the wrist axis at pin 620. Another pivotpin defines axis 605.

Six cables actuate the separate members 600-603 of the tool. The cablingmay travel through the instrument insert stem (section 303) and througha hole in the base 600, wrapping around a curved surface on link 601,and then attaches on link 601. Tension on one set of cables rotates thelink 601, and tension on other cables operates the upper and lower grips650 and 652, about axis pin 605. The cabling is provided in pairs toprovide an opposing action operation, including opposite routing paths,on the opposite sides of the instrument insert.

The set of cables that control the jaws travels through the stem 302,303 and though holes in the base 600. These cables then pass between twofixed posts 621 that constrain the cables so that they passsubstantially through an axis 620A, which defines the rotational motionof the link 601. This construction allows free rotation of the link 601with essentially no length changes in the cables that actuate the jaws.In other words, these cables, which actuate the grips 650 and 652, areeffectively decoupled from the motion of link 601. These cables passover rounded sections and terminate on grips (or jaws) 650 and 652,respectively. Tension on one pair of cables rotate grips 650 and 652counter-clockwise about axis 605. Another set of cables provides theclockwise motion to grips or jaws 650 and 652, respectively. The ends ofthe cables can be secured at the jaws 650 and 652 with the use of anadhesive such as epoxy glue, or the cables could be crimped or pinned tothe jaw.

The instrument 16 slides through the guide tube 17 of adaptor 15, andlaterally engages the adaptor coupler 230 pivotally mounted to the basepiece 234. The base piece 234 is rotationally mounted to the guide tube17, and is affixed to the linear slider or carriage 226. The carriage226, in turn, is pivotally mounted at the pivot 225 about the axis 225A.

The embodiment of the invention illustrated in FIGS. 2-4 employs a fixedwrist pivot. An alternate construction is shown in FIGS. 5-8 in whichthere is provided, in place of a wrist pivot, a controllable flexing orbending section. In FIGS. 5-8, similar reference characters are used formany of the parts as they correspond to elements found in FIGS. 2-4. Theconstruction in FIG. 5 may be employed with a stem section such asillustrated in FIGS. 3 and 4 with a curved guide tube.

In the embodiment illustrated in FIGS. 5-8, the tool 18 includes anupper grip or jaw 650 and a lower grip or jaw 652, supported from a link601. Each of the jaws 650, 652 as well as the link 601, may beconstructed of metal, or alternatively, the link 601 may be constructedof a hard plastic. The link 601 is engaged with the end of the flexiblestem section 303. In this regard reference may also be made to FIG. 4that shows the ribbed or fluted plastic construction of the flexiblestem section 303. Alternatively, the section 303 may be smooth, at leastat its distal end, as shown at 304 in FIG. 5. In still anotherembodiment both sections 302 and 303 can be rigid depending upon theparticular application.

FIG. 5 shows only the end of the stem section 303 (at 304), terminatingin bending or flexing section 660. Section 660 may be integrally formedwith the rest of section 303. This section 660 is controllably bendableor flexible usually from a remote location such as in accordance withthe telerobotic system 10 of FIG. 1. The stem section 303 is preferablyconstructed so as to be flexible and may have either fluted or smoothouter surfaces. Also, at the flexible section 660, flexibility andbending is enhanced by a bellows configuration 662 having saw-toothshape of peaks and valleys as shown in FIG. 8. The distal end of thebending section 660 terminates with an opening 666 for receiving the end668 of the link 601. The bellows configuration may be made of a singlepiece of material. Alternatively, the bellows configuration 662 may bemade of segments connected together, for example, by welds. In any case,the bellows configuration 662 is a unibody construction.

In the embodiment shown in FIGS. 5-8, the bending or flexing section 660is constructed to have orthogonal bending movements to provide bothpitch and yaw movement of the tool. This is accomplished by using fourcables separated at 90.degree. intervals. These four cables include thecables 606, 607, 616, and 617. The operation of cables 606 and 607provides flexing in one degree-of-freedom while an addeddegree-of-freedom (orthogonal to the just mentioned onedegree-of-freedom) is provided by operation of cables 616 and 617. Asillustrated in FIG. 8, these cables extend through the bellows abouthalf way between each peak and valley and thus run in parallel but closeto the outer periphery of the flexible section 660. Each of the cables606, 607, 616, and 617 terminate in a respective ball end 606A, 607A,616A, and 617A, tensioned against an end wall 615. These same cablesalso are supported by and extend through retainer block 621. Withinsection 304 these cables also run near the outer wall as shown to theleft in FIG. 8 where cables 616 and 617 are illustrated.

As for the operation of the tool, the cables 608, 609, 610, and 611extend through the flexible stem section 303 and also through theretainer block 621, flexing section 660, and the wall 615. These cablesextend to the respective jaws (650, 652) to control the operationthereof in a manner similar to that described previously in connectionwith FIGS. 2-4.

As is apparent from FIGS. 6-8, within the bellows 662, the toolactuation cables extend through the center of the bellows and aresupported and retained between block 621 and wall 615 by the centersheath 290. The center sheath 290 may be constructed of a soft plasticmaterial, and has an inner diameter sufficient to receive the bundle ofcables, and an outer diameter that fits with little clearance againstthe inner diameter of the bellows 662. The sheath 290 extends betweenthe block 621 and the wall 615 and is dimensioned to hold the cables, asa bundle, at the center axis of the bellows section. Keeping the bundlenear the center axis provides proper de-coupling between the variousdegrees-of-freedom.

Also, within the bellows 662 each of the cables is contained in its owncable sleeve 292. These sleeves are sufficiently stiff to maintainconstant cable lengths within the flexible or bendable section. In FIG.8 these sleeves are shown extending between retainer block 621 and wall615. As shown in the right most portion of FIG. 8, the cables are shownextending from the sleeve when the cables reach the end tool. FIG. 8also illustrates the aforementioned twisting of the cables that assistsin providing the de-coupling action between the tool operation and thecontrolled flexing or bending. The cables are twisted about 180 degreesbetween the block 621 and wall 615. The bellows section itself, may havea length of about one to three inches. Also, more than one bellowssection may be used to provide controlled bending at more than onelocation. In that case separate control cabling is used for each section(see, e.g., FIG. 21 described later).

As with the earlier described embodiment, the limited twisting of thecable bundle prevents the formation of kinks or loops in individualcables that might occur if the cables were left straight and parallel toone another. This twisting also de-couples certain degrees of motions,so that actuation of one of the degrees-of-freedom does not cause aresponding action at another degree-of-freedom. The twisting occursbetween the block 621 and the location where the bundle enters the wristjoint, i.e., the entry to base 601. By twisting the cables through 180degrees, the placement of all the cables is displaced from one end ofthe bundle to the other by 180 degrees. The individual cable sleevesalso define a substantially fixed length pathway for each cable so thateven though the instrument may move or rotate the cable lengths stay thesame within the section 660.

The cross-sectional view of FIG. 8 gives details of the cabling inbending section 660. The sheath 290 extends essentially between block621 and wall 615 and houses the twisted cables/sleeves. The individualsleeves 292 can be considered as terminating at respective ends inblocks 621 and 631. Each of the sleeves may be glued or secured in anyother appropriate manner in its supporting end block. This prevents thesleeves from moving axially as the cables are activated. The sleeves arepreferably constructed of a plastic that is flexible and yet hassufficient rigidity so they do not kink when the cables are activated.The sleeves also define fixed length pathways that do not compress orelongate as the cables are operated.

The 180 degrees twist in the cables/sleeves occurs essentially betweenblocks 621 and 631. This “twisting” of the center cables/sleeves allowsthe section 660 to be controllably bent, while preventing or minimizingany transfer of motion to the tool operating cables. Similarly, thisarrangement also prevents cross-coupling from the tool operation to thebending control, so that the tool operation alone does not cause anyundesired bending of the section 660.

Referring now to FIGS. 9-13 there is shown another embodiment thatincludes bellows which can be bent of flexed in a controllable manner,for example, through a user interface like that shown in FIG. 1. Similarreference characters are used in FIG. 9 as those used in describing theembodiment of FIG. 5. Unlike the embodiment shown in FIG. 5, theembodiment of FIG. 9 provides a single cable (or rod) actuation thatsimplifies the instrument construction, particularly at the tool end ofthe instrument. The single actuation is possible because the flexiblesection has two degrees-of-freedom to provide both pitch and yaw.

In the embodiment illustrated in FIGS. 9-13, the tool 18 includes anupper grip or jaw 650 and a lower grip or jaw 652, supported from ahousing 670. Each of the jaws 650, 652, as well as the housing 670, maybe constructed of metal, or alternatively, the housing 670 may beconstructed of a hard plastic. The housing 670 is engaged to theflexible stem section 303 with the bellows 662. The flexible stemsection 303 can be a ribbed or fluted plastic construction like thatshown in FIG. 4, or alternatively, the section 303 may be smooth asshown at 304 in FIG. 9.

In FIG. 9 the jaws are operated from a single push/pull cable 672 thatextends through the instrument stem and through the bellows 662 of theflexible or bendable section 660. The cable is centered in the varioussections as depicted in FIG. 9 so that when the bendable section isactivated, no movement is transferred to the tool actuation cable. Inessence, the bellows section 662 expands on one side and compresses onthe other side, leaving the center portion unchanged in length, and thusnot effecting the cable action. The jaws themselves are supported by alink bar arrangement shown at 675 that is appropriately secured at thedistal end of the cable 672. In the position shown in FIG. 9 the jawsare open, but by pulling on the cable away from the jaws the proximalend the link bar 675 pivots and closes the jaws 650, 652.

FIG. 9 shows only the end portion of the stem section 303, i.e., theportion at 304, terminating in bending or flexing section 660. Thissection 660 is bent or flexed in a controllable manner usually from aremote location as depicted FIG. 1. The stem section 303 is preferablyconstructed to be flexible and may have either fluted or smooth outersurfaces. Also, at the bending or flexing section 660, flexibility andbending is enhanced by means of constructing this section with a bellowsconfiguration 66 having peaks and valleys in a saw-tooth shapearrangement as illustrated in the cross-sectional view of FIG. 9. Thedistal end of the bending section 660 has an opening for receiving theend of the housing 670. A wall 615 is positioned at the distal end ofthe bellows 662.

In the embodiment shown in FIG. 9, the bending or flexing section 660can be bent to provide both pitch and yaw degrees of motion to the tool.This is accomplished by using four cables 606, 607, 616, and 617 thatare separated at 90.degree. intervals. The operation of cables 606 and607 provides flexing in one degree-of-freedom while anotherdegree-of-freedom is provided by the operation of cables 616 and 617. Asillustrated in FIG. 9, these cables extend through the bellows abouthalf way between each peak and valley of the respective bellows, andthus are parallel and near the outer periphery of the flexible section660. Each of the cables 606, 607, 616, and 617 terminates in arespective ball end 606A, 607A, 616A, and 617A, tensioned against theend wall 615. These cables also are supported by and extend throughretainer block 621. Within section 304 these cables also run near theinner surface of the outer wall of the section 304, as shown to the leftin FIG. 9 where cables 616 and 617 are illustrated.

As mentioned previously, the single actuation cable 672 provides all theaction that is required to operate the tool, which simplifies theconstruction of the instrument and makes it easier to keep the singlecable centered in the instrument. To accomplish this, there is provideda supporting sleeve 680 that receives the cable 672 with a snug fit. Thesleeve 680 (FIG. 10) is preferably constructed of a polyethylene plasticsuch as PEEK which has the flexibility to flex with bending at thesection 660, but at the same time is sufficiently rigid to properlyretain and hold the supported cable 672 to enable the cable to readilyslide within the supporting sleeve 680 when performing its function.Sleeve 680 defines a fixed length for the cable and does not allow anyexpansion or compression of the cable or sleeve. The sleeve 680 mayextend from the wall 615 back through the retainer block 621 and intothe flexible section of the instrument, as shown in FIG. 9.Alternatively, the sleeve 680 may extend only through the section 660and terminate at block 621.

In addition to the sleeve 680, there is provided, about the sleeve 680,a helical spring 682 having an outer diameter to allow it to fit snuglywithin the inner diameter of the bellows 662. Note that there is arelatively close fit between the cable 672, sleeve 680, and helicalspring 682 within the bellows 662. Opposite ends of the helical spring682 are located between the block 621 and wall 615. FIG. 10 shows thespring shape and the relationship of the helical spring to the sleeve680 and the actuation cable 672. In FIG. 10, the coils of the spring areshown spaced apart, but they can be more closely spaced then shown orcompletely closed.

The spring 682 may be free-floating about the sleeve 680, and ispreferably not engaged in any passage in the end supports, such as thepassage in block 621. The sleeve 680, on the other hand receives thecable 672 and is fixed in position relative to block 621 and wall 615.Passages are provided in block 621 and wall 615, and a glue or othersecuring arrangement is preferably used to hold the sleeve fixed at theblock 621 and wall 615. The spring 682 is also used as a filler orspacer between the sleeve 680 and the bellows 662 inner surface. Thespring provides a fixed position spacer since it is typically a metal,and thus will maintain the centering of the sleeve/cable, and yet isalso flexible enough to bend when the section 660 is bent in acontrolled manner. The sleeve itself is preferably made of plastic suchas PEEK which has sufficient strength to receive and guide the cable,yet is flexible enough so that it will not kink or distort, and thuskeeps the cable in a proper state for activation, and defines a fixedlength for the cable.

By maintaining the sleeve 680 fixed in position at the block 621 andwall 615, the cable length at the center axis of section 660 does notchange when the section 660 is bent. That is, the bellows shortens onone side and expands on the other side while keeping the center axislength unchanged. In this way when bending occurs at section 660 thereis no transfer of motion to the cable 672 which could undesirably movethe jaws. Hence, the bending motion is de-coupled from the tooloperation motion, and vice versa.

FIG. 11 is a cross-sectional view taken along line 11-11 of FIG. 10showing the centered cable 672, plastic sleeve 680, and the helicalspring 682. FIG. 12 is a similar cross-sectional view but for analternate embodiment using only the center cable 672 and the sleeve 680.In FIG. 12 the sleeve 680 is larger in outer diameter in comparison tothe sleeve shown in FIG. 11 so that there is a proper and close fitbetween the sleeve and the inside of the bellows.

FIG. 13 is a cross-sectional view through another embodiment of thecable support. This embodiment also has the center cable 672 containedwithin the sleeve 680, but in place of the spring 682 there is insteadused a spacer 681 made of, for example, plastic, to keep the sleeve andcable centered in the bellows. The spacer 681 may be constructed of asofter plastic than the sleeve 680, or may be made of a plastic foammaterial.

One of the benefits of the embodiment of FIG. 9 is that only a singlecable is necessary to activate the tool. Recall that the pitch and yawof the tool is controlled at the flexible wrist section 660 shown inFIG. 9. This arrangement lends itself to making the tool disposable orat the very least detachable from the instrument body so that it can bereplaced with a substitute tool. A detachable embodiment of the presentinvention is illustrated in FIG. 14 and the companion views are shown inFIGS. 15-20. Besides being detachable this arrangement also makes itpossible to provide at least a resposable and preferably a disposableinstrument tip or tool.

In FIG. 14 a disposable tip is illustrated in conjunction with aflexible shaft or tube having a remotely controllable bending or flexingsection 700. The medical instrument may include an elongated shaft, suchas shaft section 710 shown in FIGS. 14 and 15, having proximal anddistal ends, and a tool, such as graspers 702 and 704, supported fromthe distal end of the elongated shaft and useable in performing amedical procedure on a subject. The distal end of the elongated shaftand the tool have respective removably engaging portions that arereadily engagable for positioning the tool at the distal end of theelongated shaft, and readily disengageable for removal of the tool fromthe distal end of the elongated shaft. The tool may be detachable tofacilitate substituting another tool, or the tool may be constructed tobe readily disposable. The removably engaging portions may besnap-fitted together, or, as illustrated here, may be provided by ascrew interlock between the distal end of the instrument shaft and thebase or housing of the tool. Also, other forms of detachable engagingportions are considered as falling within the scope of the presentinvention.

As shown in FIG. 14, the detachable or disposable tool is used with aflexible controllably bendable section. In another version thedisposable tool can be used with a wrist pivot or even a pair ofsuccessive wrist pivots that are orthogonal to one another for providingpitch and yaw movement at the tool. The disposable tool in this versionis also preferably actuated by a single actuation element, cable or thelike.

In FIGS. 14 and 15, in a manner similar to that shown in FIG. 9, thetool is actuated by a single tendon or cable 736 that extends throughthe flexible section 700. To provide the pitch and yaw action at thetool, the bending or flexing section 700 is constructed to haveorthogonal bending movements by pulling on four cables 706, 707, 716,and 717 separated at about 90.degree. intervals, and by using a centersupport 726 with ribs 712 extending from the center support 726 anddefining slots 714 between adjacent ribs, as depicted in FIG. 15. Theribs 712 extend from a center support 726 that has extendingtherethrough a passage for receiving the cable 736 positioned within asheath 730. The ribs 712 also provide a guide structure to the fourcables 706, 707, 716, and 717. The bending section 700 is a unibodyconstruction that extends from the end of tube section 710, which itselfmay be flexible, and it may be smooth as shown, or may be fluted asillustrated in FIG. 4.

This version enables the bending section to be bent in orthogonaldirections by the use of the four cables 706, 707, 716, and 717. Theoperation of cables 706 and 707 provides flexing in onedegree-of-freedom while another orthogonal degree-of-freedom is providedby the operation of cables 716 and 717. Each of the cables 706, 707,716, and 717 has at their terminating ends respective balls 706A, 707A,716A, and 717A that may be held in corresponding recesses in a distalend wall 719 of the flexible section 700. Note that in place of theslotted bending section 700, a bellows arrangement such as shown in FIG.5 or 9 can be used.

The structure shown in FIGS. 14-17 preferably includes a plasticstiffener sheath or sleeve 730 that surrounds the cable 736, and thatfits closely within the passage of the center support wall 726. Thesleeve 730 is preferably constructed of a polyethylene plastic such asPEEK which has enough flexibility to flex with the bending section 700,but at the same time is sufficiently rigid to properly retain, centerand hold the supported cable to allow the cable 736 to readily slidewithin the supporting sleeve 730 in performing its function. The sleeve730 may extend from the distal end of the flex section 700, back throughthe passage in the wall 726, and into the shaft section 710 of theinstrument, as shown in FIG. 15.

Referring to FIG. 15A there is shown an alternate embodiment for thebending section 700 in which the sleeve 730 is eliminated. In this case,the passage in the wall 726 is dimensioned to directly and snuglyreceive the cable 736 with a close tolerance fit but having sufficientclearance to allow the cable to readily slide in the instrument.

The grippers 702 and 704 are supported for opening and closing by theuse of a pivot pin 735 that extends along axis 735A in a housing 740.Referring to FIG. 16 there is shown in partial cross-section the housing740, pin 735, and grippers 702 and 704. The pin 735 may be supported atits ends on opposite sides of housing 740. The tool also includes apivot linkage 742 that intercouples the grippers with the actuationcable 736 such that as the linkage is moved in the axial direction bythe cable 736 to open or close the jaws (or grippers). In FIG. 15 thelinkage and tool are shown in solid outline in the closed position,which corresponds to a “pulling” of the cable in a direction away fromthe tool. FIG. 15 also shows, in dotted outline, the linkage andgrippers in an open position, which corresponds to a “pushing” of thecable in a direction toward the tool. The grippers themselves areprevented from any axial movement by the support at pin 735, so when thelinkage is operated from the cable 736 the resulting action is eitheropening or closing of the grippers, depending upon the direction oflongitudinal translation of the actuating cable 736.

For the tool shown in FIGS. 14-17 to be detachable there is providedremovably engaging portions, which in the illustrated embodiment areformed by mating threaded portions. Further, these mating portions areprovided both with respect to the actuation element (cable) as well asthe stationary components of the tool and tube. Thus, the tool housinghas a threaded portion 746 with female threads, and the distal end ofthe flexible section 700, as shown in FIG. 16, has a threaded portion748 with male threads. The end of the actuation cable 736, as shown inFIGS. 16 and 17, is terminated at block 750, passing through a centerpassage in the threaded portion 748. The block 750, interacting witharms 751, allows longitudinal sliding of the cable 736, but preventsrotation thereof so that the tool can be screwed onto the shaft withoutrotating the actuation cable. The block 750 supports a male threadedshaft 753 that is adapted to mate with the tool. The threaded portion at753 may have twice the threads per length as the threaded portion 748.Also, the block 750 interacts with the arms as the tool is fully engagedto compensate for differences in thread pitch between the engagingmembers.

As previously indicated, the tool grippers are operated with the linkage742. FIG. 17 shows the end of this linkage supporting a female threadedpiece 760. To engage the tool with the instrument shaft, the femalepiece 760 is threaded onto the male threaded shaft 753 in the directionindicated by the rotational direction arrow 770.

Referring to FIGS. 18-20, there is shown the sequence of steps to attachthe instrument tip to the shaft of the instrument. These views aresomewhat schematic and are for the purpose of merely illustrating thesteps taken in attaching the tool to the instrument shaft.

In FIG. 18 the tool is first illustrated with its housing 740 about toengage at threaded female piece 760 with the corresponding threaded maleshaft 753. It is noted that the threads of pieces 760 and shaft 753 arefiner that the threaded portions 748 and 746. Also, the threaded piece760 and shaft 753 are designed such that only about four turns arenecessary to fully seat these members together. On the other hand thesections 746 and 748 have courser threads so that it takes, say, onlyabout two turns to engage the two sections together. When the tool isfully engaged there is a detent arrangement provided between theinterlocking members to lock them in their final position. This is shownin the drawings by interlocking tab 780 of housing 740, and recess 782associated with the flexible section 700.

FIG. 19 illustrates the positions of the various components after twoturns have occurred between threaded shaft 753 and threaded piece 760,and the other outer mating threaded sections are to engage. Next thethreaded portions 746 and 748 engage and after two more turns of thetool, the tool is fully engaged with the shaft, as illustrated in FIG.20. In that position the detents are also engaged so that the tool is,in essence, locked to the instrument shaft and ready for use. It is alsonoted in FIG. 20 that because of the difference in thread pitch betweenthe fine and course threads, the block 750 is free to move inward awayfrom the tool.

Referring now to FIG. 21, there is shown an embodiment having adetachable and disposable tool, and particularly adapted for applicationto a flexible instrument including a catheter. Features of the earlierdescribed embodiments may be used with the embodiment of FIG. 21. Again,although not necessary, in a preferred embodiment the tool is operatedremotely in a telerobotic manner from a user device such as shown inFIG. 1. The use of multiple controllably bendable segments as shown inFIG. 21 is particularly advantageous in a flexible instrument to assistin guidance thereof such as, for example, in vessels or arteries.

FIG. 21 shows primarily the distal end of a flexible instrument with themore proximal portions of the instrument being supported and driven in amanner similar to that illustrated in FIGS. 1 and 2. Rather than havingonly one bending or flexing section as described above, the flexibleinstrument 800 has two bending sections 810 and 815 spaced along theinstrument shaft that are remotely actuable. In other configurations,these sections 810 and 815 can be formed directly in series, and morethan two controllable segments can be used. A tool 820 is positioned atthe distal end of the instrument, and is preferably constructed to bedisposable and may be substantially the same as the tool illustrated inFIGS. 14-17 including the interengaging portions for detachability ofboth the tool body and the tool actuation element. As shown in FIG. 21,a cable 825 is used as the actuation element. Also illustrated in FIG.21 are instrument transition segments 830 and 835, which may besimilarly constructed as the flexible section 303 shown in FIG. 4.Alternatively, one or both of these sections 830, 835 may be rigid.

In each of the instrument sections shown in FIG. 21 the actuationelements (cables) that are not used to operate a particular section runpreferably through the center of the respective section to provide theproper de-coupling between the various degrees of movement. Thus, thecenter cable bundle 840 through the section 810 includes the cables tooperate section 815 and the tool 820.

If the two controllable sections 810 and 815 are controlled with bothpitch and yaw movements, then four cables are used to actuate eachsection. Thus, the actuation of each section is similar to the actuationof the embodiments shown earlier in FIGS. 5 and 9. The aforementioned“twisting” concept is also preferably used in each of these sections810, 815 where multiple cables are running through them, particularly insection 810 where five cables extend along the center of the section(four for actuation of the section 815 and one for tool actuation)similar to that shown in FIG. 8.

Thus, nine cables extend through section 830, five in the center bundle840 and four extending through and about the periphery of section 810 toprovide the controlled bending of section 810. FIG. 21 shows two ofthese cables terminating at 812 and used to operate and move the section810 with one degree of freedom. Two other cables (displaced about 90degrees) also terminate at the same general area and are used to operatethe bending section 810 with the other degree-of-freedom.

Next, in section 835 four cables at 836 branch outwardly and terminateat the end of section 815 at 837 to control the flexing of section 815.In section 815 there is thus only the single tool actuation cable 825contained in a sheath extending through the center of the section.Although FIG. 21 shows only two of the cables 836 for controlling one ofthe degrees-of-freedom of movement of the section 815, there are twoother cables (displaced about 90 degrees) that also terminate at thesame location for the other degree-of-freedom of control of section 815.Again, reference to FIG. 8 can be made for the operation of the bendingmovement of the sections with the use of the cables.

The instrument shown in FIG. 21 may be used for any number of differentsurgical procedures. Flexible instruments of this general type are shownin co-pending applications that have been incorporated herein byreference in their entirety. Although FIG. 21 shows four cables that areused to actuate a respective bending section, more or fewer cables canbe used in each section. For example, if only one degree-of-freedom isdesired in section 810 then only two actuating cables are employed tocontrol bending in only one plane. The instrument may also be controlledfor rotation to provide another degree-of-freedom.

In the embodiment of the invention shown in FIGS. 14-17, the tool isreadily disposable. By providing a bendable section that can controlboth pitch and yaw movement of the tool, the tool itself becomesactuable with a single cable or rod. Now, FIGS. 22 and 23 disclose in aschematic manner this same disposability feature as applies to aninstrument, whether flexible or rigid, that employs a wrist pivot orwrist and elbow pivot.

FIG. 22 is a schematic diagram of the instrument illustrating both elbowand wrist pivot joints, as well as the disposable tool. FIG. 23 showsjust a wrist pivot joint with a disposable tool. More specific detailsof portions of the diagrams can be found in earlier embodimentsdescribed herein.

In FIGS. 22 and 23 like reference characters are used to identify likeparts. In FIG. 22 there is provided an instrument 900 that includes bothan elbow joint 905 and a wrist joint 910. These joints allow fororthogonal motions of the various segments about respective axes 905Aand 910A. Both of these joints are driven by cabling in a manner asdescribed earlier, such as in the pivot arrangement shown in FIGS. 3 and4. This cabling preferably runs through the center of the instrument aspreviously described. The instrument 900 also includes an end tool 920driven from a cable or rod 925. This tool construction and its actuationelement may be the same as described in FIGS. 14-17, and would includeseparate interengagable/disengageable portions as previously described.

In FIG. 23 there is shown an instrument 930 that includes only a singlewrist joint 910, along with the tool 920 actuated by means of theactuation element 925. Again tool 920 is preferably readily detachablein the manner shown in FIGS. 14-17 and is thus readily disposable. Toprovide another degree-of-freedom the instrument may be controllablyrotated as indicated by the arrow 927 in FIG. 23.

FIG. 24 illustrates a wrist or other joint that may be used for thejoints shown FIGS. 22 and 23. FIG. 24 shows a ball joint 950 withintercoupling sections 951 and 952. An actuation cable 954 is alsoillustrated extending through sections 951 and 952 as well as throughthe middle of the joint 950. The joint 950 may be of a conventional typeusing mating outer pieces at 956 that enable the sections 951 and 952 tohave relative rotation therebetween. At least within the joint itself,there is provided a sheath 958 that encloses the cable 954, and that ispreferably fixed in position at the top and bottom of the joint. Thesheath is flexible and yet sufficiently durable so as to define a fixedlength for the cable to extend through, even as the joint is actuated torotate or pivot.

Appropriate cabling may be provided for control of the joint 950. Thistype of joint is particularly advantageous in that the center of thejoint is open and does not interfere at all with the passing of theactuation cable 954 and sheath 958 through the joint 950. Again, bymaintaining the cable at the center of the joint, as illustrated, evenas the joint is actuated there is no adverse effect on the actuationcable. In other words as the joint rotates it does not change the lengthof the cable 954, and thus these separate actions are de-coupled fromeach other.

Referring now to FIG. 25, a further description of a wrist or otherjoint is illustrated that may be used for the joints shown in FIGS. 22and 23. FIG. 25 shows a ball joint 960 intercoupling sections 961 and962. An actuation cable 964 is also illustrated extending throughsections 961 and 962 as well as through the middle of the joint 960.Here again, the joint 960 may be a conventional joint using mating outerpieces at 966 that enable the sections 961 and 962 to have relativerotation therebetween. Within the joint itself, there may be provided asheath that encloses the cable 964 and that may be preferably fixed inposition at the top and bottom of the joint.

Appropriate cabling may be provided for control of the joint 960. Inthis particular joint rather than being completely open as in FIG. 24there is provided a funnel like surface illustrated at 970 that directsthe cable to an output orifice 972 where the cable is coupled into thesection 962. This funnel surface 970 holds the cable such that as thesections experience relative rotation while the length of the cablewithin the joint is maintained at a fairly fixed length.

Other embodiments of the tool 18 are within the scope of the invention,such as that illustrated in FIGS. 26-33. A set of jaws is illustrated inthe figures, but it is understood that other types of tool constructionsmay also be used with the concepts of the present invention. Also, theinstrument shaft may be a rigid shaft, a flexible shaft, or combinationsthereof.

The tool 18 includes four basic members including the base 1020, link1021, upper grip or jaw 1022 and lower grip or jaw 1023. The base 1020is affixed to the instrument shaft 1010. The instrument shaft 1010 maybe rigid or flexible depending upon the particular use. If the shaft1010 is flexible it may be constructed, for example, of a ribbed plasticmaterial. A flexible shaft or section thereof would, in particular, beused in conjunction with a curved guide tube so that the instrumentreadily bends through the curved adaptor guide tube.

In the embodiment of FIGS. 26-33, link 1021 is rotatably connected tothe base 1020 about wrist pivot axis 1025 with a wrist pivot pin at1026. The upper and lower jaws 1022 and 1023 are rotatably connected tothe link 1021 about axis 1028 with a pivot pin 1030, where axis 1028 isessentially perpendicular to axis 1025. The jaws may also be referred toas grippers or graspers.

Six cables 1036-1041 actuate the wrist, namely the link 1021, as well asthe end effector or tool 18. Cable 1036 extends through the instrumentshaft and through a hole in the base 1020, wraps around curved surface1032 on link 1021, and then attaches on link 1021 at 1034. Tension oncable 1036 rotates the link 1021, as well as the upper and lower jaws1022 and 1023, about axis 1025. Cable 1037 provides the opposing actionto cable 1036, and goes through the same routing pathway, but on theopposite side of the instrument shaft. Cable 1037 is also attached tolink 1021 generally at 1034.

Cables 1038 and 1040 also travel through the instrument shaft 1030 andthough holes in the base 1020. The cables 1038 and 1040 then passbetween two fixed posts 1035. These posts constrain the cables to passsubstantially through the axis 1025 about which the link 1021 rotates.This construction allows the link 1021 to rotate freely with minimallength changes in cables 1038-1041. In other words, the cables1038-1041, which actuate the jaws 1022 and 1023, are essentiallydecoupled from the motion of link 1021. Cables 1038 and 1040 pass overrounded sections and terminate on jaws 1022 and 1023, respectively. Theapplication of tension on cables 1038 and 1040 rotate jaws 1022 and 1023counter-clockwise about axis 1028.

Finally, as shown in FIG. 27, the cables 1039 and 1041 pass through thesame routing pathway as cables 1038 and 1040, but on the opposite sideof the instrument. These cables 1039 and 1041 provide the clockwisemotion to grips or jaws 1022 and 1023, respectively. The ends of cables1038-1041 may be secured at 1033 of the jaws 1022 and 1023.

In addition to the jaws 1022 and 1023, the tool 18 includes a rotationpiece 1045, a linkage 1046 and slotted linkage 1048. The rotation piece1045 has a centrally disposed hole 1045A that is adapted to receive thepivot pin 1030. The pivot pin 1030 also passes through holes 1023A inone jaw member and holes 1022A in the other jaw member. The pin 1030 issecured in respective holes in the arms 1029 of the link 1021 in awell-known manner to rotatably support the jaw members from the link1021. The rotation piece 1045 also carries an actuation pin 1050extending in the same direction as the pivot pin 1030, and parallelthereto. The actuation pin 1050 extends into curved J-shaped slots 1052in respective jaw flanges 1054 of jaw 1023.

The actuation pin 1050 is also received by the linkage 1048 through theend hole 1048A, and the linkage is supported between the spaced flanges1054 of the jaw 1023. At the slotted end of the linkage 1048 there is aset of holes 1048B that receive the pin 1056. The linkage 1048 alsopivotally attaches with the linkage 1046 by virtue of the pin 1056passing through the holes 1046B and 1048B. The pin 1056 is alsopositioned in the slots 1052 of the flanges 1054, and thus moves alongthe slots to different positions, two of which are illustrated in FIGS.30 and 31. When the jaws are fully closed, the pin 1056 is at the verytop of the slot 1052 as illustrated in FIG. 31. FIG. 30 shows the pin1056 in a lower position which occurs when the jaws are partiallyopened. The pin 1050 likewise is in different positions in the slot 52depending upon the position of the jaws.

The linkage 1046 is also supported at its other end at hole 1046A by thepin 1058. The pin 1058 also passes through a set of holes 1022B in thebase of the jaw 1022. The linkage 1046 fits in a slot at the base of thejaw 1022, and the pin 1058 passes through both the base of the jaw 1022as well as the linkage 1046. The pin 1058 also preferably has acompliant member such as a set of resilient members disposed about atleast a portion thereof, as illustrated in FIGS. 30 and 31, at 1060, inan uncompressed position. FIG. 31 shows the resilient cups 1060uncompressed, while FIG. 32 shows the resilient cups partiallycompressed when the jaws are grasping a small diameter member such as asuture S. FIG. 33 shows the cups 1060 essentially fully compressed, whenthe jaws are grasping a larger diameter member such as a needle N. Thecups 1060 may fit about the pin 1058, and be disposed in the base of thejaw 1022. The holes 1022B that receive the cups 1060 are of somewhatelongated shape, such as illustrated in FIGS. 27A, 27B, 30, and 31.

With further reference to FIGS. 32 and 33, the jaws 1022 and 1023 applya smaller but sufficient force to hold a smaller diameter item, such asthe suture S than when holding a larger item such as a needle N. Thisforce is primarily a function of the resiliency of the cups 1060. Thus,the larger the diameter of the item being held, the larger thecorresponding holding force. The tool is constructed so that when thejaws are holding an item the size of a needle N the cups 1060 areessentially fully compressed, and a maximum grasping force is applied tothe needle N. This is particularly desirable for important surgerytechniques for the securing and controlling of the needle. When the jaws1022 and 1023 first make contact with an item positioned between them,the pin 1056 is in a contact position A′ (FIG. 33) for a larger itemsuch as the needle N, or further up the slot 1052 at a position A (FIG.32) for a smaller item such as the suture S. When a sufficient force isapplied to the item with the jaws, the pin 1056 moves to a lockedposition B (FIGS. 32 and 33), regardless of the size of the item beinggrasped.

Other embodiments of the resilient members are shown in the fragmentaryexploded views of FIGS. 27A and 27B. The embodiment of FIG. 27A uses apair of cups 1060A, while the embodiment of FIG. 27B uses only a singlecup. In FIGS. 27A and 27B the same reference characters are used as inFIG. 27 to identify like components. In the embodiment of FIG. 27A thecups 1060A are positioned within respective holes 1022B. They may bepositioned with the use of an adhesive. The cups 1060A are thus belocated at opposite ends of the pin 1058. When the jaws are in theclosed position, these cups 1060A are compressed as the pin 1058 ridesdownwardly in the somewhat elongated hole or slot 1022B. In theembodiment of FIG. 27B the single cup 1060B is of somewhat larger shapethan the cups 1060A and is located between the spaced walls of the base1022C. The link 1046 is positioned between these walls, as is the cup1060B. The cup 1060B may also be secured in position by an adhesive. Thecup 1060B is engaged by the end of the link 1046. In this embodiment thepin 1058 also rides within the elongated slots 1022B and when the jawsare moved to a closed position the end of link 1046 bears against thecup 1060B. In still another embodiment one may use all three cups toprovide additional resiliency.

The actuation cables for the end effector include the cables 1038-1041.One set of cables actuates the rotation piece 1045, while the other setof cables actuates the jaw 1023. The other jaw 1022 is actuated throughthe coupling provided from the rotation piece 1045 to the jaw 1022,including pin 1050 and the associated linkages 1046 and 1048 controlledvia pins riding in slots 1052. These linkages provide direct drive fromthe rotation piece 1045 to the base of the jaw 1022, to control thepivoting motion of that jaw, controlled usually from a remote location.

Another embodiment of the tool 18 is illustrated in FIGS. 34-38, whereFIG. 34 is a perspective view of the tool while FIG. 35 is an explodedperspective view showing the separate components of the tool. In thisembodiment the same reference characters are used to designate similarcomponents.

The tool 18 shown in FIGS. 34-38 includes four basic members including abase 1020, a link 1021 attached to the base, an upper grip or jaw 1022,and a lower grip or jaw 1023. The base is affixed to an instrument shaftin a manner similar to that depicted in FIG. 26. As before, theinstrument shaft may be rigid or flexible depending upon the particularuse.

In the embodiment shown in FIGS. 34-38, the link 1021 may be rotatablyconnected to the base about a wrist axis such as the axis 1025 of thejust previously described embodiment. The upper and lower jaws 1022 and1023 are rotatably connected to the link 1021 about axis 1028 with a pin1030 that is substantially perpendicular to axis 1025.

Six cables 1036-1041 actuate the wrist, namely the link 1021, as well asthe end effector or tool 18. Cable 1036 extends through the instrumentshaft and through a hole in the base, wraps around curved surface 1032on link 1021, and then attaches on link 1021 at 1034 (FIG. 35). Tensionon cable 1036 rotates the link 1021, and the upper and lower jaws 1022and 1023, about the wrist axis. Cable 1037 provides the opposing actionto cable 1036, and goes through the same routing pathway, but on theopposite side of the instrument shaft. Cable 1037 is also attached tolink 1021 generally at 1034.

Cables 1038 and 1040 also travel through the instrument shaft and thoughholes in the base. The cables 1038 and 1040 then pass between two fixedposts that are similar to the posts 1035 in FIG. 26. These postsconstrain the cables so that they pass substantially through the wristaxis about which the link 1021 rotates. This construction allows thelink 1021 to freely rotate with minimal length changes in cables1038-1041. Hence, the cables 1038-1041, which actuate the jaws 1022 and1023, are decoupled from the motion of link 1021. Cables 1038 and 1040pass over rounded sections and terminate on jaws 1022 and 1023,respectively. The application of tension on cables 1038 and 1040 rotatejaws 1022 and 1023 counter-clockwise about axis 1028.

Finally, as shown in FIG. 35, the cables 1039 and 1041 pass through thesame routing pathway as cables 1038 and 1040, but on the opposite sideof the instrument. These cables 1039 and 1041 provide the clockwisemotion to jaws 1022 and 1023, respectively. The ends of cables 1038-1041are secured at 1033 of the jaws 1022 and 1023.

In addition to the jaws 1022 and 1023, the tool 18 includes the rotationpiece 1045, along with linkage pair 1066 and straight linkage 1068. Therotation piece 1045 has a central hole 1045A that receives the pivot pin1030. The pivot pin 1030 also passes through holes 1023A in one jawmember and hole 1022A in the other jaw member. The pin 1030 is securedto respective holes in the arms 1029 of the link 1021 to rotatablysupport the jaw members from the link 1021. The rotation piece 1045 alsocarries an actuation pin 1050 extending in the same direction as thepivot pin 1030, and parallel thereto. The actuation pin 1050 extendsinto curved slots 1052 in respective jaw flanges 1054 of jaw 1023, asshown in FIGS. 35, 37, and 38.

The actuation pin 1050 is also received through an end hole 1068A of thelinkage 1068, and the linkage is supported between the spaced flanges1054 of the jaw 1023. At the other end of the linkage 1068 there is ahole 1068B that receives the pin 1076. The linkage 1068 also pivotallyattaches with the linkage pair 1066 by virtue of the pin 1076 passingthrough the holes 1066B and 1068B. The pin 1076 is also positioned inthe slots 1052 of the flanges 1054, and thus moves along the slots todifferent positions, two of which are illustrated in FIGS. 37 and 38.When the jaws are in a substantially closed position, the pin 1076 is atthe top of the slot 1052 as illustrated in FIG. 37. When the jaws are inother positions, the pin 1050 will reside in different positions in theslot 1052.

The linkages 1066 are also supported at its other ends at holes 1066Athe pin 1078. The pin 1078 also passes through a hole 1022B in the baseof the jaw 1022. At that point the base has a support wall 1022D inwhich the hole 1022B is located. The linkage pair 1066 fits on oppositesides of the wall 1022D, and the pin 1078 passes through both the baseof the jaw 1022 as well as the linkage pair 1066.

The actuation cables for the end effector or tool include the cables1038-1041. One set of cables actuates the rotation piece 1045, while theother set of cables actuates the jaw 1023. The other jaw 1022 isactuated through the coupling provided from the rotation piece 1045 tothe jaw 1022, including pin 1050 and the associated linkages 1046 and1048 riding in slots 1052. These linkages provide direct drive from therotation piece 1045 to the base of the jaw 1022, to control the pivotingmotion of that jaw, typically from a remote location.

In the embodiment shown in FIGS. 35-38, control of the grasping force onan item is provided primarily by means of a slot or gap in one of thejaws. This is illustrated in FIGS. 34-38 by the gap 1031 located nearthe base 1022C in the jaw 1022. FIGS. 35, 37, and 38 show in particularthe shape and depth of the gap 1031. The gap 1031 is located above ahinge 1044 where the jaw can deflect when grasping and holding an item,regardless of its size, and with a firm grasping force. The gap 1031 maybe terminated in a tubular passage 1031A to enhance the hinging effectof the hinge 1044. Hence the hinge 1044 acts as a compliance membersimilar to the resilient members 1060 described with reference to FIGS.27-33.

Referring now in particular to FIGS. 37 and 38, the jaws 1022, 1023 areshown in a substantially closed position in FIG. 37 grasping a suture S.In that position it is noted that both of the pins 1050 and 1076 aresubstantially at their top transition locations. FIG. 38 illustrates thejaws 1022, 1023 grasping an item such as a needle N that causes the jaw1022 to flex and consequently the gap 31 to close up. This flexureenables the application of a varied grasping force at the tip of thejaws. When the links are at the end of their travel, the jaw 1022 flexeswhen the jaws 102, 1023 grasp an item. The amount of flexure depends onthe diameter of the item being grasped. Thus, the jaws 1022 flexes to alesser extent when a smaller diameter item such as a suture S is beinggrasped then when a larger item such as a needle N is being held. Thatis, to grasp a smaller item, the gap 1031 closes to a lesser extent,while the jaw. As still apply a sufficient holding force to the item.This force is primarily a function of the resiliency at the gap, asdefined primarily by the flexure capability at the hinge 1044. Thelarger the diameter of the item being held, the larger the correspondingholding force. The tool is constructed so that, for an item the size ofa needle, as shown in FIG. 38, the gap 1031 is fully closed with thesides of the top of the gap touching, with a maximum grasping forcebeing applied to the needle N. This is particularly desirable for thesecuring and controlling of the needle in important surgery techniques.Here again, the pin 1076 is at a contact position A′ (FIG. 38) when thejaws first make contact with a larger item such as the needle N, orfurther up the slot 1052 at a contact position A (FIG. 37) when the jawscontact a smaller item such as the suture S. Regardless of the size ofthe item, the pin moves to a locked position B (FIGS. 37 and 38) whenthe sufficient force is applied to lock the jaws onto the item.

In connection with both of the embodiments described in respective FIGS.26-33, and FIGS. 34-38, there has been described a “locked” position Bof the pins or jaws. This locked position corresponds to a positionwherein the linkages are disposed at right angles to each other. Inother words, for example, in FIG. 31 in that locked position thelinkages 1046 and 1048 are disposed at right angles (90 degrees) to eachother. This provides virtually infinite grasping force with essentiallyno back drive at the jaws. Regarding the embodiment in FIGS. 34-38 itwould be the linkages 1066 and 1068 that are disposed at right angleswhen locked.

Reference is now made to another embodiment of the invention illustratedin FIGS. 39 and 40. This embodiment has a structure very similar to thatdescribed in detail in FIGS. 26-33. However, in place of the resilientcup 1060 there is provided a modified jaw slot configuration. Asindicated previously the slots 1052 in jaw 1023 have a curved segment1052A, and a straight segment 1052B. In this embodiment the J-slots 1052also have a contiguous end slot 1052C that extends back toward the tipof the jaw tip. Hence, the overall slot configuration is C-shaped. InFIG. 39 the jaws are in a substantially open position with a gap G1 asnoted when the jaw members 1022, 1023 are locked onto and the needle N,with the pin 1056 located at a locked position B. Before the jaws makecontact with the needle N, the pin 1056 may be out of the end slot1052C, and the pins 1050 and 1056 are located at different positionsalong the slots 1052 depending upon the degree of openness of the jaws.When the jaws contact the needle N, the pin 1056 is at a contactposition A′. In FIG. 40 the jaws are in a substantially closed positionwith a small gap G2 as the jaws grasp a smaller item such as a suture S.In this position the pin 1056 now moves further into the end slots 1052Cto the locked position B, as the jaws apply a grasping force to an itemto lock the suture between the jaws. When contact is first made betweenthe jaws and the suture, the pin 1056 is located at the contact positionA further up the slot 1052 than the contact position A′ of FIG. 39.Thus, depending upon the size thereof, the pin 1056 moves to a greateror lesser extent into the slots 1052C.

To hold a large diameter item such as a needle, the pins 1050 and 1056are in the position illustrated in FIG. 39 with there being a maximumgrasping force applied to the item by virtue of the links 1046 and 1048being positioned at 90 degrees relative to each other. For smallerdiameter items such as a suture, the pins rotate slightly furtherclockwise with the pin 1056 moving into the slot 1052C as illustrated inFIG. 40. When the pin 1056 moves into the slot 1052C, the jaw andlinkages move together as a rigid body while closing against the suture.

In sum the slots 1052C, like the resilient member 1060 (FIGS. 27-33) andthe hinge 1044 (FIGS. 37 and 38), are accommodating mechanisms thatallow a closing force to be applied to grasped items of different sizesas the force is applied to the grasped item as the jaws close to aposition at which the jaws remain open.

The accommodating mechanisms described above like the slots 1052C (FIGS.39 and 40), the resilient member 1060 (FIGS. 27-33), and the hinge 1044(FIGS. 37 and 38, can be implemented in other types of graspingmechanisms as well, such as those described in U.S. application Ser. No.09/827,643, filed Apr. 6, 2001, and U.S. application Ser. No.10/014,143, filed Nov. 16, 2001, the entire contents of which areincorporated herein by reference.

In each of the aforementioned embodiments described herein the medicalinstrument includes a jaw or work members controlled by a drivemechanism that is used to open and close the jaws or work members forapplying an increased force to an item grasped between the jaws or workmembers. The accommodating mechanisms described above such as the slots1052C (FIGS. 39 and 40), the resilient member 1060 (FIGS. 27-33), andthe hinge 1044 (FIGS. 37 and 38, each have the characteristic ofproviding a maximum grasping force at what may be considered a maximumgrasping position. This corresponds to the positions illustrated, anddiscussed previously, in FIGS. 33, 38, and 39. In each of theembodiments the instrument is constructed so that this maximum positioncorresponds to a predetermined size or diameter items that is to begrasped, usually a needle in this case. For item smaller or larger thanthis size the grasping force is progressively less. In the instance ofthe embodiment of FIGS. 26-33, for smaller items such as the suture S,the force is less because the compliant member is compressed less. Forthe case of an item larger than the needle N, the linkage does not go tothe top of the J-slot and thus the applied force is also less in thatcase, as the linkages are not yet to a maximum force 90 degree position.

In all three of the described embodiments the accommodating mechanismallows the jaws or work members to be closed beyond this maximumgrasping position in order to grasp items of various sizes, particularlysmaller size items. Again, this is illustrated by way of example in FIG.32 where the jaws go past their maximum grasping position, closing to acloser position therebetween, in grasping the suture S. In FIG. 37 thisis illustrated by the jaws closing to grasp the suture S with less forcebeing imposed by the flexure at the jaw 1022. This is also illustratedin FIGS. 39 and 40. In FIG. 39 the jaws are at their maximum graspingposition. In FIG. 40 the jaws are closed beyond this maximum graspingposition to grasp the smaller size suture S. The accommodating mechanismin this case may be considered as including the slot segment 1052C thatenables further rotation of the linkages to the position illustrated inFIG. 40.

Other embodiments of the flexible or bending segment are within thescope of the invention. For example, there is shown in FIGS. 41-47another embodiment of a flexible or bending segment with a unibodyconstruction which can be used with any suitable end effector like thetools 18 described above, whether used with a rigid shaft body or aflexible shaft body or combinations thereof. As with some of theembodiments described earlier, one of the benefits of the embodimentshown in FIGS. 41-47 is that only a single cable 1136 needs to becoupled to the tool 18 to actuate it. The pitch and yaw of the tool 18is controlled at the flexible section 1100 shown in FIG. 41. Thisarrangement also lends itself to making the tool disposable or at thevery least detachable from the instrument body to facilitatesubstituting another tool. Here again, because of the simplifiedconstruction at the tip of the instrument, a tool can be constructedthat is readily detachable from the instrument.

Although the bendable section 1100 is depicted near the tool, thebendable section can be located at other locations further away from thetool. Since the tool 18 of the embodiment shown in FIGS. 41-47 requiresonly a single actuation cable, it is simpler to operate than thewrist/tool combination shown in FIGS. 26 and 27. Recall, in the wristarrangement, a pivot axis does not accommodate single cable actuation.Thus, with the wrist unit one has to use a far more complex cablingscheme, such as, by way of example, the cabling arrangement illustratedin U.S. Pat. Nos. 6,312,435 and 6,206,903. Furthermore, the single cableactuation provides a more simplified design that readily lends itself toa variety of tool constructions.

In order for the various degrees of motions to be decoupled from eachother, and for the proper overall functioning of the distal end of theinstrument, the instrument has certain preferred characteristics,particularly at the flexible or bendable section of the instrumentshaft. These characteristics are listed below but are not in anyparticular order of significance. Embodiments can employ at least one ofthese characteristics. Furthermore, although these characteristics arelisted with reference to the embodiment described in FIGS. 41-44, one ormore of the characteristics can apply as well to any of the otherembodiments described earlier.

A first characteristic is that the actuation element for the tool becentered in the flexible or bendable section. In this way, during anybending operation the center of the flexible or bendable section tendsto maintain the same length, even though opposed outer surfaces of thesection may, respectively, expand and contract. This, in essence, meansthat the bending action is not erroneously transferred to the actuationelement for the tool, hence, de-coupling the bending operation from thetool actuation, and vice versa.

A second characteristic is that the flexible or bendable section of theinstrument shaft be readily flexible without the application of undueforce. This bendable section, in a preferred embodiment, is to haveorthogonal bending characteristics, hence providing two degrees offreedom (DOF) to the distal tool, for example, yaw and pitch. Toaccomplish this, at a particular bend location, a substantial portion ofthe flexible or bendable section is located as near to the centerneutral axis 1111 of the section as physically possible. This isachieved by the spaced rib construction including the ribs 1112 shown inthe drawings. The slots 1114 defined by these ribs 1112 provide voidareas, leaving more material near the center neutral axis, as depictedin FIG. 45. Reference has been made to a neutral axis 1111 of thebendable section 1100. In actuality there is for a particular benddirection a neutral plane that during a bend is maintained at a fixedlength.

A third characteristic relates to the torsional nature of the flexibleor bendable section. The more stiff the section is torsionally (twistingmoment) the less likely there will be an undesired twisting of thebendable section that accompanies controlled rotation thereof. In otherwords, if the bendable section is torsionally stiff, then uponcontrolled rotation of the instrument shaft, there is no an undesiredtwisting action imparted on the shaft particularly at the flexible orbendable section 1100. To accomplish this, at a particular bendlocation, a substantial portion of the material forming the flexible orbendable section is located at the periphery of the flexible or bendablesection. This may be achieved by having portions of the section extendto an outer surface. In the embodiment described here this isaccomplished by providing radial ridges, such as the ridges 1120 shownin the drawings. Furthermore, these ridges are alternated betweenhorizontal and vertical positions to, at the same time, to provide theorthogonal bending or flexing.

A fourth characteristic is that the flexible or bendable section of theinstrument shaft is constructed so that there is little or no end-to-endcompression. In other words, the flexible or bendable section maintainsa relatively constant length regardless of the motion actuations thatoccur in the multiple degrees of freedom movement of the instrument. Toaccomplish this, a stiff member is provided to maintain the ends of theflexible or bendable section at a fixed spacing. This may be achieved byproviding the stiff member as a centrally located stiff sleeve thatreceives and supports the sliding motion of the actuation element foroperation of the distal tool. This stiff member is preferably fixed atits opposite ends to the bendable section to maintain the fixed lengthof the section, thereby preventing end-to-end compression. At least partof this member may include the sleeve 1182 depicted in FIG. 43.

Referring again to FIG. 41 there is disclosed one embodiment of the tool18, used in conjunction with a flexible shaft or tube having a remotelycontrollable bending or flexing section 1100. The medical instrument mayinclude an elongated shaft, such as shaft section 1110 shown in FIGS. 41and 42, having proximal and distal ends; and the tool 18 with jaws 102and 104, supported from the distal end of the elongated shaft anduseable in performing a medical procedure on a subject. In FIGS. 42 and43 the tool 18 is actuated preferably by a single tendon or cable 1136that extends through the flexible section 1100. In order to provide thepitch and yaw action at the tool, the bending or flexing section 1100 isconstructed to bend in orthogonal directions with the use of four cablesseparated at about 90.degree. intervals and by using a center supportwith ribs and slots about the entire periphery of the bending section1100, as depicted in FIGS. 42-44. This orthogonal bending may also bereferred to as bi-axial bending, meaning bending in separate axes. Theribs 1112 define corresponding slots 1114, and also define at each oftheir centers a center support passage 1118 that has the cable 1136extending through it, as well as other cable support members describedin further detail later. The bending section 1100 extends from the endof tube section 1110, which itself may be flexible, may be smooth asshown, or may be fluted, and may have other controllable bendingsections disposed along its length.

To bend the bending section 1100 in orthogonal directions, use is madeof the four cables 1106, 1107, 1116 and 1117. The operation of cables1106 and 1107 provides flexing in one degree-of-freedom while an addedorthogonal degree-of-freedom is provided by operation of cables 1116 and1117. Each of the cables 1106, 1107, 1116, and 1117 have at theirterminating ends respective balls 1106A, 1107A, 1116A, and 1117A thatmay be held in corresponding recesses in a distal end wall 1119 (FIG.45) of the flexible section 1100.

The bending section 1100, as indicated previously, includes a series ofspaced ribs 1112 positioned, in parallel, with the plane of each ribextending orthogonal to the neutral axis 1111 of the section 1100. Atthe proximal end of the bendable section, an end rib connects to theshaft section 1110, while at the distal end there is provided the distalend wall 1119 that supports the ends of the cables. Each of the ribs1112 are held in spaced relationship by means of the alternating ridges1120. As depicted in FIG. 43 these ridges are identified as horizontalridges 1120A, alternating with vertical ridges 1120B. This structureprovides support at the center passage for the actuating cable 1136,while also providing torsional strength to prevent undesired twisting atthe shaft section 1100.

The jaws 1102 and 1104 are supported for opening and closing by means ofa pivot pin 1135 that extends along a pivot axis. These grippers may besupported in link 1140, and the pin 1135 may be supported at its ends inopposite sides of link 1140. The tool also includes a pivot linkage 1142that intercouples between the grippers and the actuation cable 1136. Thepivot linkage 1142 includes linkages 1142A and 1142B. At one end, eachof the linkages 1142A and 1142B connects to respective jaws 1104 and1102. At the other end, the linkages 1142A and 1142B are pivotallysupported at end 1137 of cable 1136. Opposed pins extend from end 1137for engagement with the linkages 1142A and 1142B. The jaws 1102 and 1104are shown having recesses 1102A and 1104A for accommodating therespective linkages 1142B and 1142A.

In FIG. 42 the jaws 1102 and 1104 are shown in their open position withthe linkages 1142A and 1142B shown in a forward pivoted configuration.FIG. 43 illustrates the jaws 1102 and 1104 in a closed position with thelinkages 1142A and 1142B shown in an in-line configuration. As thelinkage 1142 is moved in an axial direction by the cable 1136, thisaction opens and closes the jaws or grippers. This corresponds to a“pushing” of the cable in a direction toward the tool. FIG. 43, on theother hand, shows the linkage and grippers in a closed position. Thiscorresponds to a “pulling” of the cable in a direction away from thetool with the specific linkages 1142A and 1142B shown in an in-lineconfiguration in their final closed position. The grippers themselvesare prevented from any axial movement by the support at pin 1135, sowhen the linkage is operated from the cable 1136 the resulting action iseither opening or closing of the grippers, depending upon the directionof forward-to-back translation of the actuating cable 1136.

The structure shown in FIGS. 41-47 preferably also includes a plasticcable sheath 1180, a plastic stiffener sheath or sleeve 1182 thatsurrounds the cable 1136 and the sheath 1180, and that fits closely inthe center passage 1118, and an outer silicon spacer 1184. The sleeve1182 is preferably constructed of a polyethylene plastic such as PEEKwhich has flexibility to allow the sleeve 1182 to bend with the section1100, but at the same time is sufficiently stiff (particularlyend-to-end) to properly retain, center and hold the supported cable toenable the cable to readily slide within the sheath 1180 and thesupporting sleeve 1182, in performing its function. In FIG. 42 thesleeve 1182 is illustrated extending from the distal end of the bendablesection 1100, back through the passage, to the more proximal end of thebendable section 1100.

Reference has been made previously to the single actuation cable 1136that provides all the action that is required to operate the tool. Thisgreatly simplifies the construction and makes it easier to keep thesingle cable centered in the instrument. As indicated previously thiscentering feature maintains the same length of the actuation element,even though opposed outer surfaces of the section itself may,respectively, expand and contract during bending. This, in essence,means that the bending action is not erroneously transferred to theactuation element, hence, the bending operation is de-coupled from toolactuation, and vice versa.

FIGS. 42 and 43 also show the use of an adhesive, at 1186, such an epoxyadhesive for anchoring opposite ends of the sheath 1180 and the sleeve1182 to opposite ends of the bendable section 1100. By maintaining thesheath 1180 and sleeve 1182 fixed in position at their ends, when thesection 1100 is controlled to bend, the cable length at the center orneutral axis of section 1100 does not change. Furthermore, at the ribbedbendable section, on one side the section shortens and on the other sideit expands while keeping the center or neutral axis length unchanged. Inthis way when bending occurs at section 1100 there is no transfer ofmotion to the cable 1136 which could undesirably move the jaws. Thebending motion is thus de-coupled from the tool operation motion, andvice versa.

Other features of the bending section are shown in FIG. 45 in a sideelevation view, while FIGS. 46 and 47 illustrate cross-sectional views,with one through one of the ridges 1120A and the other through one ofthe ridges 1120B. The respective ridges 1120A and 1120B are arranged atabout 90 degrees to each other.

As described earlier, the section 1100 is easily bendable while beingtorsionally stiff, and has other improved characteristics as well.Details of these characteristics are best described with reference toFIGS. 45-47 by considering a particular cross-section such as thecross-section in FIG. 45 taken along line 46-46. In viewing FIG. 45 itis clear that, at that location and with the orientation of the section1100 as shown, there is a substantial void created by the slot 1114, sothat the majority of the section material is located at the center ofthe section. This is consistent with the desired bendability at thatlocation, since, in general, a structure becomes more bendable as itsdiameter decreases. The void area mentioned is also illustrated in thecross-sectional view of FIG. 46 at 1115.

To understand how the bending section 1100 can be torsionally stiffwhile also being bendable, reference is also made to the same locationat the line 46-46, but with the section rotated through 90 degrees. Thisis the same as looking at the cross-sectional view depicted in FIG. 47.In other words, one is thus considering the location through the ridge1120A. The section 1100 is constructed so that there is preferably arelatively large center passage 1118, leaving more material toward theouter periphery, which is desired for providing enhanced torsionalstiffness. Note that this material is the material of the ridge itself.Thus, for torsional stiffness it is desired to have a void near themiddle and more material located away from the middle.

The rib and ridge arrangement shown in the drawings thus provides in asingle structure a bendable section that provides two degrees of freedom(biaxial motion) that is also torsionally stiff. The bendingcharacteristics enable the transfer of two degrees of freedom to thetool, rather than just one degree of freedom as with a conventionalwrist joint. The torsional stiffness enables direct rotational transferto the tool through the bendable section and without any twisting at thebendable section.

Mention has been made previously of the four characteristics of thebendable section described herein. The first characteristic relates tothe centering of the actuation element. This is carried out primarilywith the use of the center passage and the associated sheath 1180,sleeve 1182, and the spacer 1184. The second characteristic relates tothe ease of bending. This is accomplished primarily with the ribbedconstruction with void peripheral areas. The third characteristicrelates to the torsion stiffness that is accomplished primarily by thealternating ridges. Lastly, the fourth characteristic relates to theend-to-end compression. To prevent the bendable section from compressingfrom end-to-end during an operation, particularly during tool actuation,to facilitate proper tool operation, the center passage is provided withthe stiff sleeve 1182, and the opposite ends of the sheath 1180 andsleeve 1182 fixed in place, and the section 1100 has a ridgedconstruction.

It is noted that FIGS. 41-47 disclose one version of an end effectoremploying jaws 1102 and 1104, in combination with, linkage 1142.However, other tool constructions are also contemplated as fallingwithin the scope of the present invention including ones that provide amechanical advantage at the tip of the jaws or other work elements.

Also, in various embodiments described herein only a single cable isused for tool actuation. (See, for example, FIGS. 9, 15, and 42.) Inthese embodiments it is preferable to provide at least the opposite endsof the actuation cables with enhanced stiffness, particularly where thecable is unsupported. For example, in FIG. 42 this might be in thedistal section of cable 1136 exiting from wall 1119 to the jaws of thetool. This stiffness can be provided by treating the ends of the cablewith a harder metal coating, or by other means that will provide astiffer end section.

Turning now to FIGS. 48A-48D, there is illustrated yet anotherembodiment of a flexible section 1660 with a unibody construction. Thetool 18 attached to the distal end of the flexible section 1660 includesan upper grip or jaw 1602 and a lower grip or jaw 603, supported from alink 1601. Each of the jaws 1602, 1603, as well as the link 1601, may beconstructed of metal, or alternatively, the link 1601 may be constructedof a hard plastic. The link 1601 is engaged with the distal end of theflexible stem section 1302. FIG. 48C shows the distal end of the stemsection 1302, terminating in a bending or flexing section 1660. Also, atthe flexible section 1660, flexing and bending is enhanced by thearrangement of diametrically-disposed slots 1662 that define ribs 1664between the slots. The flexible section 1660 also has a longitudinallyextending wall 1665, through which cabling extends, particularly for theoperation of the tool jaws. The wall 1665 can also be thought of asopposed ridges that extend outward from the center of the flexiblesection 1660. The very distal end of the bending section 1660 terminateswith an opening 1666 for receiving the end 1668 of the link 1601. Thecabling 1608-1611 is preferably at the center of the flex section atwall 1665 to effectively decouple flex or bending motions from toolmotions.

To operate the tool, reference is made to the cables 1608, 1609, 1610,and 1611. All of these cablings extend through the flexible stem sectionand also through the wall 1665 as illustrated in FIG. 48C. The cablesextend to the respective jaws 1602, 1603 for controlling operationthereof in a manner similar to that described previously in connectionwith FIGS. 5-8. FIGS. 48A-48D also show cables 1606 and 1607 whichcouple through the bending section 1660 and terminate at ball ends 1606Aand 1607A, respectively, and urge against the end of the bendablesection in opening 1666. When these cables are pulled individually, theycan cause a bending of the wrist at the bending or flexing section 1660.FIG. 48D illustrates the cable 1607 having been pulled in the directionof arrow 1670 so as to flex the section 1660 as depicted in the figure.Pulling on the other cable 1606 causes a bending in the oppositedirection.

By virtue of the slots 1662 forming the ribs 1664, there is provided astructure that bends quite easily, while the wall or opposed ridges 1665provide some torsional rigidity to the flexing section 1660. The wall1665 bends by compressing at the slots in the manner illustrated in FIG.48D. This construction eliminates the need for a wrist pin or hinge.

The embodiment illustrated in FIG. 48B has a separate link 1601.However, in an alternate embodiment, this link 1601 may be fabricatedintegrally with, and as part of the bending section 1660. For thispurpose the link 1601 would then be constructed of a relatively hardplastic rather than the metal link as illustrated in FIG. 48B and wouldbe integral with section 1660.

Mention has also been made of various forms of tools that can be used.The tool may include a variety of articulated tools such as: jaws,scissors, graspers, needle holders, micro dissectors, staple appliers,tackers, suction irrigation tools and clip appliers. In addition, thetool may include a non-articulated tool such as: a cutting blade, probe,irrigator, catheter or suction orifice. Moreover, the bending sectionitself may be non-actuated. As such, even when the bending movements ofthe bending section are not controlled by a surgeon, the one or moredegrees-of-freedom of movement of the bending section allows it toconform to orifices or lumens within the patient's body as the sectionis advanced through the body.

There have been described herein a number of different embodiments ofbendable sections such as in FIG. 5, 14, 21, or 41. These may be used,as illustrated herein, in conjunction with instrument systems asdescribed in, for example, FIG. 1 where the instrument is insertedlaparoscopically. Alternatively, these concepts may also be used inflexible instrument systems more like that described in FIG. 21 whereinthe bendable sections can be located at various positions along theinstrument shaft or body. In this case the bendable section or sectionsmay be used both for guidance toward an operative site, such as forguidance through an anatomic lumen or vessel, or for operation ormanipulation at an operative site. In the more rigid system where theinstrument is meant to enter the body, for example, through an incision,such as laparoscopically, then it is preferred to have the bendablesection located close to but just proximal of the distal end effector ortool. This bendable section positioning provides for proper manipulationof the tool at the operative site. In this case the bendable sectionpreferably has a length in a range on the order of ¾ inch to 4 inches.Also, the distance between the tool pivot point and the distal end ofthe bendable section is preferably equal to or less than the length ofthe bendable section.

Referring to FIG. 49, an example of a flexible instrument 2000 is shownin use in a stomach 2002 of a patient. The instrument 2000 includes anelongated portion 2004, which itself is flexible, and an articulatedbendable section 2006. Any embodiments of the tool 18 described can bemounted at the terminal end of the bendable section 2006. The bendablesection 2006 can be any one of the different embodiments describedearlier such as those shown in FIG. 5, 14, 21, or 41. In operation, theflexible instrument 2000 is inserted through a body lumen such as theesophagus 2008, and the tool 18 is directed to the operative site 2009.As shown, the instrument 2000 can lean against some element of theanatomy such as a wall 2010 of the stomach to brace the instrumentduring the medical procedure, while the bendable section 2006 and thetool 18 are articulated as described above.

In certain implementations, as shown in FIG. 50A, a flexible instrument2100 may include a bendable section 2102 that can be operated with oneor more pull cables 2104 to manipulate the tip 2106 of the bendablesection. The tip 2106 may be provided with an embodiment of the tool 18described above that is positioned at the operative site to perform amedical procedure. At least one cable 2104 is attached at or near thetip 2106 of the bendable section 2102, and extends from its point ofattachment through an aperture 2108 at a position spaced a selecteddistance along the length of the bendable section 2102 away from thedistal end. The remainder of the cable 2109 extends from the aperture2108 through a shaft 2110 of the instrument 2100 and is coupled, forexample, to a drive unit 8, like that described earlier, that applies atension to the cable 2104 to controllably bend the bendable section2102.

The bendable section 2102 may have a circular cross section, or in someembodiments, the bendable section is provided with one or more groovesor valleys 2112 (FIG. 50B) along its length. As such, while theinstrument 2100 is inserted into the patient, the cables 2104 lie alongthe grooves 2112, which prevents the cables 2104 from inadvertentlycatching any body element. As appropriate tension is applied to aparticular cable, it effectively “pops” out of the groove 2112 as thetip of the bendable section 2102 is pulled towards the aperture 2108.For certain embodiments of the tool 18, the bendable section 2102 isprovided with a center tube 2114 through which the actuation element forthe tool 18 extends.

While this invention has been particularly shown and described withreferences to preferred embodiments thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the scope of the inventionencompassed by the appended claims. For example, mention has been madeof the bi-axial bending of the bendable section of the instrument.However, the principles of the present invention may also apply to abendable section that has only one degree-of-freedom, in which case thebendable section would only be controlled by one set of control cablesrather than the two sets described earlier.

This invention can be implemented and combined with other applications,systems, and apparatuses, for example, those discussed in greater detailin U.S. Provisional Application No. 60/332,287, filed Nov. 21, 2001, theentire contents of which are incorporated herein by reference, as wellas those discussed in greater detail in each of the following documents,all of which are incorporated herein by reference in their entirety:

U.S. Pat. Nos. 6,197,017 and 6,432,112, PCT Application Ser. No.PCT/US00/12553 filed May 9, 2000, and U.S. application Ser. No.09/827,643, filed Apr. 6, 2001, 10/034,871, filed Dec. 21, 2001,10/270,741, filed Oct. 11, 2002, 10/270,743, filed Oct. 11, 2002,10/270,740, filed Oct. 11, 2002, 10/077,233, filed Feb. 15, 2002, and10/097,923, filed Mar. 15, 2002.

1. A medical instrument assembly, comprising: an elongated shaft havinga proximal end and a threaded distal end; a tool carried by the distalend of the elongated shaft for performing a medical procedure on apatient, the tool including an end effector, a threaded housing in whichthe threaded distal end of the shaft is configured for being screwed,and a first threaded piece disposed in the threaded housing andconfigured for being moved to actuate the end effector; and an actuationelement extending within the elongated shaft, the actuation elementincluding a second threaded piece that distally extends from thethreaded distal end of the elongated shaft, the second threaded piececonfigured for being screwed to the first threaded piece of the tool. 2.The medical instrument assembly of claim 1, wherein the first threadedpiece has more threads per inch than the threads of the threadedhousing.
 3. The medical instrument assembly of claim 1, wherein thefirst threaded piece is centered within the threaded housing.
 4. Themedical instrument assembly of claim 1, wherein the end effectorincludes a pair of jaw members that open and close when actuated, andthe tool further includes linkage coupled between the jaw members andthe first threaded piece, such that axial movement of the actuatingelement opens and closes the jaw members.
 5. The medical instrumentassembly of claim 1, wherein the second threaded piece is configured forbeing linearly displaced relative to the threaded distal end of theelongated shaft.
 6. The medical instrument assembly of claim 5, whereinthe actuating element includes a block proximal to the second threadedpiece, and the threaded distal end of the elongated shaft includes apair of arms configured for engaging the block to prevent the secondthreaded piece from rotating relative to the threaded distal end of theelongated shaft.
 7. The medical instrument assembly of claim 1, whereinthe first threaded piece has female threads, and the second threadedpiece has male threads.
 8. The medical instrument assembly of claim 1,wherein the elongated shaft is a cable.
 9. The medical instrumentassembly of claim 8, wherein the actuation element further includes asleeve disposed about the cable to prevent compression of the cable. 10.The medical instrument assembly of claim 9, wherein the actuationelement further includes a helical spring disposed about the respectivesleeve.
 11. The medical instrument assembly of claim 1, furthercomprising: a controllably bendable section associated with elongatedshaft and disposed proximal to the tool; another actuation elementconfigured for actuating the controllably bendable section; and meansfor decoupling motion at the controllably bendable section from the toolactuation.
 12. The medical instrument assembly of claim 1, furthercomprising an instrument coupler mounted to the proximal end of theelongated shaft, the instrument coupler carrying a rotatable wheel towhich the actuation element is mounted.
 13. The medical instrumentassembly of claim 12, further comprising an adapter coupler to which theinstrument coupler is configured for being removably mated, the adaptercoupler having a complementary wheel that mechanically interfaces withthe wheel of the instrument coupler.
 14. The medical instrument assemblyof claim 13, further comprising cabling extending from the adaptercoupler and configured for coupling a drive unit to the complementarywheel.
 15. The medical instrument assembly of claim 12, furthercomprising a carriage on which the instrument coupler is mounted.
 16. Arobotic medical system, comprising: the medical instrument assembly ofclaim 1; a user interface configured for generating at least onecommand; a drive unit coupled to the actuating element of the medicalinstrument assembly; and an electric controller configured, in responseto the at least one command, for directing the drive unit to move theactuating element to actuate the tool.
 17. The robotic medical system ofclaim 16, wherein the at least one command comprise movements made atthe user interface, and wherein the electric controller is configuredfor directing the drive unit to move the actuating element to effectmovements of the tool corresponding to the movements at the userinterface.
 18. The robotic medical system of claim 16, wherein the userinterface is located remotely from the drive unit.
 19. The roboticmedical system of claim 16, wherein the electrical controller is coupledto the drive unit via external cabling.
 20. The robotic medical systemof claim 16, wherein the drive unit has a motor array.
 21. The roboticmedical system of claim 16, wherein the drive unit is coupled to theactuating element via external cabling.